As a core material of a seat of a vehicle such as an automobile, a vehicle seat member in which a frame member is integrally molded on a foamed resin molded body is known (Patent Literatures 1, 2, and the like).
Patent Literature 3 discloses a method of manufacturing a vehicle seat core material by embedding a locking fixture to be fixed to a vehicle and a connecting member for connecting it in a thermoplastic resin foamed particle molded body and integrally molding them. The connecting member is embedded on a front side of the foamed particle molded body along a longitudinal direction of the seat core material. Patent Literature 3 discloses that outward in the longitudinal direction of the seat core material of the foamed particle molded body part in which a column part of the locking fixture is embedded, a space or a notch going outward from the column part in the seat core material longitudinal direction is formed.